During the Live Earth concert, it was hard to take the trooping celebrities seriously. “I turn off lights!” “I drive a hybrid!” Today, after hearing more of this, I wondered how much of this really makes a difference. I half-expect to hear next: “I turn off a light before I blow-dry my hair for an hour!” Or: “On my trip to Paris, Rome and Tokyo, I turned off my iPod seven times to save energy!”  Or (as a marketing ploy): “Go to a movie theater, where hundreds of people can watch a single screen! Saves lots more energy than turning on 100 TVs!”